This R34 application proposes to further develop and pilot an early intervention for depression during the preschool period. The specific aim of the proposed study is to further modify and adapt a proven effective manualized dyadic early intervention for preschool disruptive disorders, Parent Child Interaction Therapy (PCIT, Eyberg, 1988), for application to preschool depression. The proposed treatment entitled PCIT- Emotion Development (ED) has been modified to include additional treatment components that focus on "emotion development". The new ED module addresses deviations in early emotional reactivity from a developmental perspective and is based on an emotion development model of mood disorders. PCIT-ED is proposed as a developmentally sensitive early intervention strategy for childhood depression focused on strengthening the parent-child relationship and utilizing the parent as an "arm of the therapist". The mediating role of parenting support in preschool depression severity has been previously established supporting the notion that the dyadic relationship is an ideal target for early intervention in depression. PCIT has been previously successfully adapted for application to anxiety disorders. The validity of a clinical preschool depressive syndrome has now been established in two independent study samples. Evidence of a specific and stable symptom constellation, family history of related disorders, biological correlates, and observational evidence of low enthusiasm have been found. Replication of these validation findings as well as new evidence for significant impairment in developmental and adaptive functioning based on independent raters in multiple contexts has also been established. These findings confirm the clinical significance of this early onset depressive syndrome and the need for intervention for during the preschool period. A 2-stage study is proposed, beginning with an "open case series" during which each treatment session will be systematically assessed and the manual will be modified to maximize acceptability and fidelity. This will be followed by a pilot feasibility study in which N=30 subjects will be randomized to PCIT-ED or an active parenting education control condition. In keeping with evidence of greater efficacy of earlier intervention in several mental disorders, intervention for depression during the preschool period may provide a window of opportunity for greater therapeutic efficacy during a period of rapid developmental and neurobiological change. The public health need for novel and earlier interventions in depression is underscored by the lack of available safe and clearly effective treatments for prepubertal children. PHS 398 (Rev. 09/04) Page Form Page 2 The public health goal of this project is to find new and potentially more effective methods for treating childhood depression. The project focuses on the earliest possible identification of depression and the use novel therapeutic approaches that target the parent-child relationship. This is needed because depression is a serious and chronic disorder for which there are currently few safe and effective treatments established.